


Because You Need Me

by Moro



Category: Shingeki no Kyojin | Attack on Titan
Genre: Anal Sex, Bisexual Character, Bisexuality, Complicated Relationships, F/M, Fluff and Smut, M/M, Mildly Dubious Consent, Multi, One Shot, Oral Sex, Voyeurism
Language: English
Status: Completed
Published: 2013-11-14
Updated: 2013-11-14
Packaged: 2018-01-01 11:23:05
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,810
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1044246
Author URL: https://archiveofourown.org/users/Moro/pseuds/Moro
Summary: <blockquote class="userstuff">
              <p>Mikasa doesn't trust Eren with important things on his own... and that includes even the most intimate things...</p><p>Set during their time in the Training Corps before the battle for Trost.</p>
            </blockquote>





	Because You Need Me

            Armin came to find Eren not long after everyone had been dismissed for the day.  His shoulders and wrists ached but at least he hadn’t done as terribly today as other days…

            He found Eren hiding in his room, seemingly having managed to dodge Mikasa for the time being.  Or possibly she had left him alone of her own will, to give him some space.  Either way, he was alone in the room, gazing fixedly at the floor from his seated position at the edge of the bed.  He looked exhausted.

            “Eren?”  

            “Oh, it’s only you, Armin,” Eren said, relaxing a little.  A pause.  “What are you doing here?”

            “I came to see you.  I was worried… you left suddenly, so…”

            Eren made an irritated sound. “Tch, I don’t want _you_ watching me all the time like I need protecting or something, too, it’s bad _enough_ with Mikasa always doing that.”  There was that sharp edge to his voice that indicated he was in danger of losing his temper, and Armin almost flinched, not used to Eren actually directing it at him.

            “T-that’s not what I meant!” Armin protested.  He ran a hand through his hair distractedly.  “It’s not like…I don’t think you need protecting.  Eren, I’m not …it’s just…”  Suddenly he felt very uncomfortable just standing in the doorway.  “Look, can I come in?”

            Eren’s gaze softened a little.  “Yeah.” 

            Armin sat carefully on the bed next to him, turning slightly to face him.  As usual, Eren gave off the impression of a rubber band drawn tight, full of that constant edginess, nervous energy, restlessness.  Eren seemed incapable of actual relaxation and Armin thought that he often woke looking no less exhausted than he had before going to sleep, deep shadows perpetually surrounding his piercing green eyes.  It lent him a constant look of intensity that was both frightening and compelling still, even accustomed to it as Armin was.

            The silence seemed to stretch for an eternity, and Armin glanced awkwardly around the room, not knowing what to do. 

            It was Eren who spoke first, and when he did his voice was strangely subdued.

            “You’re not allowed to die, understand?”  He rolled his shoulders, wincing a little.

            “I—I’m… I won’t!” Armin sputtered.  “I’m… sorry I can’t take care of myself, but…”  He felt tears rising in his eyes and quickly reached up to wipe them away, but suddenly Eren seized his hand, squeezing so hard it almost hurt.  Despite the strength of his grip, his hand was shaking.

            “Don’t be.”  Eren’s voice serious, softer still.  “You’re not a burden, Armin.”  His shoulders were shaking, and it was hard to tell if the unsteadiness in his voice was anger, or something else.  Eren was not normally difficult to read…he wore his feelings on his sleeve, but…

           “I’m sorry that I… that I can’t keep up,” Armin muttered sadly, looking away.  “I should just… I’ll just slow you down in the Survey Corps.  I’m sorry…”

           “No.”  Eren’s voice was hard again and Armin jumped.  “You have to stay with me.”  He ran a hand through his hair.  “So I can protect you.”

           “Eren, y-you…” He squeezed his eyes shut, but a few tears rose and streaked down his face anyway. 

            “Don’t leave me,” Eren said suddenly, pulling Armin close, clinging to him as if afraid he would disappear.  More startling was when he reached up to thread his fingers through the other boy’s hair, with a strange and very uncharacteristic gentleness, and rested his head in the crook of Armin’s neck.

            “I… I won’t,” said Armin.  “E-even though I slow you down…?”  He sniffled.  “Eren, I couldn’t…I _can’t_ live without you.”  He almost hadn’t meant to say it, but…  “W-we have to see the outside world, together!”

           And now Eren really _was_ crying, though very quietly for him, tears trickling down his face, onto Armin’s shoulder.  Armin felt lips softly touch the side of his neck.  “I don’t want to live without you,” Eren whispered. 

           Armin shivered, a tingling radiating out from where Eren had kissed him spreading out to the rest of his body.  He could feel Eren’s heart hammering in his chest, his own racing, a flush creeping rapidly over his face.

            “E-Eren, I…”  The words caught in his throat, how to say _please Eren I’m yours I’ve always been yours touch me more please_ and so instead he nudged at Eren’s shoulders, to get the other boy to face him, hoping to convey with his eyes what he couldn’t find the words for.

            Eren’s green eyes seemed very bright as he looked at Armin.  He saw a succession of feelings flash over Eren’s face—sadness, confusion, and then _yes_ there it was, that confusion shifting to hope and…unmistakably, _desire_.  Armin flushed, smiled, and nodded.

            It was like a dam had been broken—Eren took hold of Armin’s shoulders and pushed him determinedly down onto the bed, climbing on top of him and kissing him _hard,_ his tongue all but forcing into his mouth.  Armin squeaked and then moaned softly, leaning up towards him and wrapping an arm around his waist…Eren’s body felt impossibly hot, his mouth even more so—it almost made him dizzy.   When Eren broke away he was panting for breath and Armin felt dizzier still.  Eren’s eyes were wide as he looked down at Armin, almost as if _he_ were surprised at what he was doing.

            Armin reached up toward him, roughly grabbing one of the leather straps of the 3D Maneuver Gear harness to pull him closer, to kiss him again…he’d thought many times of how it would feel to kiss him, and it definitely wasn’t far off from how he’d imagined it—Eren was aggressive on the edge of being rough, as he’d always assumed he would be—but he didn’t just kiss him, he _devoured_ him, as if his life depended on the feeling of Armin’s mouth, his lips, his tongue.  It was almost overwhelming.   

           Eren had pinned him and, it seemed, was trying to touch him everywhere at once, hands sliding beneath his shirt to caress his sides, his chest, working to undo his belt.  His hands, like all of the trainees’, were roughened and calloused from hours upon hours of drilling, but Armin shivered with every touch, small soft noises escaping him.  He could feel Eren’s clothed erection pressing against his own and the faint pressure made him squirm.  He was only aware that Eren had succeeded in unfastening the belt when he felt his hand sliding into his pants.   

           “E-Eren— _ah!_ ” The sudden friction felt startlingly good, and then Eren was forcing Armin’s pants down just enough to take hold of his cock, not wanting to take the time to unstrap the harness and remove them properly, slowly stroking him.  Armin shuddered and moaned, eyes squeezed shut in embarrassment…how many times, while doing this himself had he imagined it was Eren’s hand on him just like this?  Shakily Armin reached forward to press his hand against Eren’s still-clothed cock, and the sharp intake of breath he got in response… _yes, more, come on…_ He rubbed his hand against him somewhat awkwardly but he seemed to be doing all right, if the faint sounds coming from Eren’s mouth were any indication.

           Armin had just started attempting to undo Eren’s belt himself when the door swung open.  Both of them froze. 

           “Should’ve known.”  Mikasa stood in the doorway, wearing her typical detached expression.

           Armin seemed to have lost the ability to speak entirely, and had gone a truly spectacular shade of red.  Eren found his voice much more rapidly, with characteristic fury.

           “Mikasa _what_ the _fuck_ are you doing here?!” he spat, gesturing sharply down at Armin as if it wasn’t already perfectly obvious what they had been doing.  Armin shrank back and hid his face behind his hands with a whine, feeling that what he would most like to do was to crawl into a corner and die.

           Mikasa almost seemed to be _studying_ the two of them, with little more emotion than if she were considering a new combat technique.  She seemed to take little lascivious interest at all if her facial expression was any indication, although there was a subtle blush painting her cheeks.  Mostly, she seemed to be thinking very hard.

           “Well, Eren, you don’t know what you’re doing,” she said, with the same infuriatingly cool and patronizing tone she always used for him, and carefully shut the door behind her, quickly shrugging off her jacket and tossing it aside.

           “Mikasa, _seriously—_ ” 

           “I know you don’t want to mess this up,” she replied matter-of-factly, gesturing vaguely at Armin and crossing over to the bed.  Watching over Eren as always, keeping him from ruining everything, naturally.  He cared about Armin so much, this happening had been inevitable anyway.  It would never do to have it botched by Eren’s usual carelessness…she couldn’t forgive herself if he ruined something that mattered so much to him because she didn’t help.

           Eren looked utterly mortified and Armin squeaked again, still refusing to show his face.  Perhaps if he hid from everything for long enough, it would just go away, or he might sink into the bed and out of existence entirely.

           “ _What—no, don’t_ come over here _why—_ ” and Eren had barely gotten the words out of his mouth before Mikasa had comfortably seated herself on the bed next to them.  Eren felt vaguely pinned by the intensity of her gaze and he hissed as she suddenly grasped the back of his head, pulling _hard_ on his hair, and forced his head down between Armin’s legs.

           “Use your mouth on him.  It’ll make him feel good.  _Do it_ ,” she ordered, and Eren did not even have a choice as she took hold of Armin’s cock—Armin’s hands immediately dropped from his face, his eyes wide—and then forced it into Eren’s mouth.  Armin made a choked shriek that abruptly transitioned into a moan, hips snapping up to meet Eren’s mouth—if his hand had felt good then his mouth felt _amazing,_ hot and wet and the way his tongue moved…  And the entire time, Mikasa’s hand remained firmly on the back of Eren’s head, guiding him, forcing his up-and-down movements, and Armin felt confused and turned on all at once.  Mikasa had succeeded in completely dominating Eren within a minute of entering the room…well, that wasn’t really anything new.  Eren whimpered softly, Mikasa’s grip on his hair stung fiercely every time she pulled his head up, and when she held him all the way down Armin’s cock almost choked him, but the noises Armin was making… and he hated to admit it, but there was _something_ about how utterly under her control he was…

           Casually, Mikasa reached towards Armin with her free hand, brushing her fingertips over his nipples.  He gasped as she rolled and pinched them between her fingers…in truth he’d never really thought of what _her_ touch would feel like, but her skillful fingers seemed to indicate a level of experience that Eren clearly did not have.  He didn’t have the presence of mind to wonder where that experience could have come from.

           “Hmm, I thought so,” Mikasa noted mildly.  She finally let go of Eren’s head and he surfaced with a gasp.  Armin whimpered softly at the loss and attempted to prop himself up on his elbows, but immediately Mikasa roughly shoved him back down, holding him easily with one arm, and he squirmed—being held down by Eren _and_ Mikasa was a mix of scary, and…it was too embarrassing to admit that such helplessness at their hands only made him harder, more desperate to be touched. 

           “Um, Mikasa…”

           As soon as his mouth wasn’t full, Eren began protesting again.  “Mikasa, _damn it_ will you just _get out_ —” and his string of furious objections would probably have carried on forever had she not cut him off by kissing him.  Her kiss was slow, deep and precise, and when she sucked _hard_ on his tongue he moaned and shivered in spite of himself.  He could still hear Armin’s quiet panting and wondered what Mikasa was doing to him.  A strand of saliva extended momentarily between them when she released him and he felt quite suddenly short of breath. 

           “Like that, see.  Now kiss him.”  Not wanting to simply obey, but wanting her to physically _force_ it even less, Eren half-shoved her out of the way with a low growl and complied, attempting to copy how she’d kissed him, telling himself it wasn’t because _she_ had done it, but because of the way it had felt, and Armin’s soft moaning into his mouth showed he liked it as much as Eren had. 

           Mikasa made a little noise that sounded vaguely like approval.  “Good.”  Eren dipped his head down to take one of Armin’s nipples into his mouth, rolling it delicately between his teeth and Armin whimpered, shakily running his hand through Eren’s hair, over the back of his neck. 

           Mikasa deftly jerked Armin’s pants down a bit further, and it wasn’t hard to guess what she was trying to gain access to but Eren knew there was no point in trying to stop her…and as much as he hated to admit it, she _did_ seem to be making a difference, if Armin’s reaction was any indication.  He wasn’t entirely sure how to feel about it. 

           Eren worked to undo his own belt and pants—he was so hard it was almost painful, his cock straining against the close-fitting fabric.  He had barely managed to free his cock before Mikasa’s slicked fingers—fuck, when had she done that?!—had closed around it.

           Eren broke the kiss with a hiss and shuddered as she touched him—her fingers were strong and _squeezing_ and she kept doing this _thing_ with the tips of them around the head of his cock with every stroke that made sparks dance at the corners of his vision.  He tried to choke back his cries and failed miserably.  Suddenly Armin arched his back with a harsh gasp and Eren saw that she had slid her slicked longest finger smoothly inside him, slowly thrusting, and Armin whimpered desperately as she gradually added a second, then a third.

           A chaotic mix of emotions bounced around in Eren’s head—frustration, jealousy, shock, nervousness, confusion—all overshadowed by how good her hand felt and how Armin looked beneath him, one hand thrown over his face and helplessly writhing, his whole body shaking every time Mikasa’s fingers slid back inside him. 

           Eren’s own pleasure was cut short as Mikasa released his cock from her hand, and her breath was suddenly hot on his ear as she leaned in to murmur, “He’s moaning now, but he could be _screaming_ …that’s what you want, isn’t it?”  Eren growled something incoherent just as Mikasa withdrew her fingers, leaving Armin feeling oddly empty.

           “ _Dammit_ Mikasa I don’t have to _tell_ you, you _know_ I want him, will you just _let me do it_!” The words came out in a continuous stream and while Mikasa had merely whispered, Eren almost shouted.  Armin moved his hand, opened his eyes, and stared into Eren’s, almost transfixed. 

           Of course Eren wanted him, else why would he have started…all of this (for that matter it wasn’t as if Eren even seemed concerned with his own pleasure, too focused on touching Armin) but to actually hear him say it…he felt tears welling in the corners of his eyes and fought to hold them back.  He didn’t want to embarrass himself any further by crying…and if he did cry, Eren might think he was upset, and stop… He cried enough as it was anyway.

           “Eren…I, um, want you too, so, please…”  And Eren _smiled_ and…wait, was that a smile on _Mikasa’s_ face, for a moment?  There was a momentary brightness in her usually hollow, dull dark eyes that betrayed her, but _what_ she was actually feeling was difficult to say.  Mikasa was the opposite of Eren—where he wore his emotions brilliantly on his sleeve, she was always guarded, impenetrable.  Her gaze was fixed entirely upon Eren.  She held his chin, forcing him to look at her, pulling him so close he could feel her breath on his lips when she spoke, and he shivered involuntarily.

           “ _Do it_ , then,” Her voice sharp, commanding, and a shudder chased down Armin’s spine.  “ _Fuck him_.”  Eren moaned softly in spite of himself… _why does it make me harder to hear her say that, fuck, what does it mean…_

           She scooted back to lean against the wall, just watching them now.  Armin found it oddly relieving that Eren was almost as flushed as he was.    

           “Please, Eren…”  Armin’s voice felt like a bolt of lightning that shot straight to his groin.  _How could I ever say no to that?_

           Eren hoisted Armin’s legs up by the harness straps, resting them on his shoulders, leaning down to kiss him roughly, and buried his cock inside him in almost a single stroke.  Armin jolted and cried out sharply, tears welling at the corners of his eyes—it _hurt_ , Eren’s cock was _definitely_ bigger than Mikasa’s fingers, and he’d had no time to adjust.  He bit down on his lip, trembling, willing himself to relax so that the stinging would subside… still, it wasn’t entirely painful.  There was a… _fullness_ that felt good in a way he couldn’t quite place, and despite the pain, his cock still throbbed against Eren’s stomach.

           And…it was _Eren_ , his protector, the one closest to him in the whole of this terrible, brutal world…if he had to endure some pain for _this_ , then it had to be all right. 

           “Be _careful_ with him, stupid,” Mikasa admonished, but Armin barely heard her as Eren kissed him slowly, gently as if to be apologetic.

           “Sorry,” Eren said quietly.  He hadn’t meant to hurt him…  He softly ran his fingers through Armin’s thoroughly disheveled blond hair.

           “It’s okay,” Armin murmured tremulously.  Eren let out a breath he hadn’t realized he had been holding and stared down at him. 

           “I t-think it’s all right, now,” said Armin.  “Just…g-go slow, at first?”  Eren swallowed and nodded, slowly drawing out, then sliding back in, carefully, and Armin gasped every time the head of his cock passed into him.  Eren made a short choked sound…Armin was almost unimaginably tight and hot, the slow thrusting was tortuous.  But the sting was subsiding somewhat and now Armin’s focus was on how incredibly hard Eren was, the way his cock stretched him and filled him.  He panted softly, hips quivering with every movement…it was starting to feel more and more like _teasing_ when Eren took him so slowly.

           “A-ah, Eren…h-harder…” 

           Eren groaned and thrust into him harder, deeper, than before—Armin yelped, arching forward to meet him—and then his cock hit _something_ inside him and Armin _screamed_ and convulsed, fingernails digging hard into Eren’s back. 

           “Oh _god_ , Eren, do that again oh god _please_ —” and Eren moaned shakily, grasping Armin’s hips to thrust into him again, harder, because when Armin _begged_ him like that how could he ever do anything but give him what he wanted?   When Armin was reduced to such high, unrestrained cries, and had become so _vocal_ now that it was only Eren touching him, moaning a torrent of near-incomprehensible words, he could make out _yes_ and _more_ and _Eren!_ He’d heard the strength of Armin’s voice before but it seemed nothing compared to now.

           “M-more— _Eren—faster_ —”

           “ _Fuck_ , Armin—!” Eren felt sparks at the edge of his vision, driving into Armin hard and fast and he clung hard to him, arching his back, hips snapping forward to meet him, to take him deeper, and with every thrust Eren rammed _hard_ into that spot inside, thrusts that made him moan without breathing.  And then Eren shakily took Armin’s cock in his hand and suddenly Armin twisted and his whole body spasmed violently—

           “ _Ah_ —I’m— _EREN—!”_

           And Armin trembled and thrashed as the orgasm wracked his body, and suddenly _Mikasa was murmuring in Eren’s ear again_ —

           “Very good.  _Now_ you can come.”  Eren couldn’t even begin to place the violent surge of emotion that exploded in his mind at her words, he swore there had been an undertone of _purring_ in her voice, and then, that was enough—he dug his hands into Armin’s hips and spent himself inside him with a whimpering, quavering cry that he hadn’t thought he was capable of making.

           It was only when Armin finally collapsed onto the bed with a soft, low groan that Eren released his grip.  Shakily he withdrew from him and slumped forward to lay with his head on his chest.  He felt Mikasa’s hand slowly stroking his hair but was too exhausted to do anything about it.

           “You did well,” she said simply, standing and putting on her jacket.  “I…I’m happy, Eren.”  It was such a strange statement coming from her and Eren started to question her, but she was already gone.

            It was silent for a few moments, just long enough for Armin to start working himself up again, before Eren said anything else.

           “Definitely can’t take off my shirt around anyone for a few days.”  He gestured to the bright red scratches covering his back, and Armin felt an odd sense of satisfaction despite Eren’s annoyance.  “I’d never hear the end of it.” 

            “Eren?”

           “Sorry, Armin.”  He had been angry and frustrated before but now, he sounded more melancholy than anything.  “Mikasa’s…you _know_ how she is.  I tried to tell her to leave, but…”  He swore under his breath and quite suddenly took Armin’s face in his hands.

           “You’re _mine,_ not hers,” he said very seriously.  “And…I don’t _belong_ to her either.” 

           Armin smiled.  “It’s all right.  I’m…I’m happy.”  And in truth he was, for the first time in he didn’t know how long.  Somehow there was an island, a possibility, to feel happy in this terrible, cruel world…it was comforting and he rested his head on Eren’s shoulder, wrapping his arm around him and squeezing him tightly.

           “I love you.”

           It had been so hard to say before but suddenly, it felt as normal as breathing.  Or crying.  And then, frustratingly, he _was_ crying, _again_ , soft sobs shaking him as he clung onto Eren as if his life depended on it.

           For once in his life Eren felt at a loss for words, so he just settled for kissing him instead.

~ * ~ * ~

            “Ha!  I _knew_ it,” Sasha snickered gleefully, rubbing her hands together.  The barracks walls clearly weren’t as thick as either Eren or Armin thought…oh, this was going to be fun.

 

 

             


End file.
